diff --git a/conformance/BUILD.bazel b/conformance/BUILD.bazel
index 52deaf52..85b6aa13 100644
--- a/conformance/BUILD.bazel
+++ b/conformance/BUILD.bazel
@@ -7,9 +7,11 @@ package(
 
 _ALL_TESTS = [
     "@com_google_cel_spec//tests/simple:testdata/basic.textproto",
+    "@com_google_cel_spec//tests/simple:testdata/bindings_ext.textproto",
     "@com_google_cel_spec//tests/simple:testdata/comparisons.textproto",
     "@com_google_cel_spec//tests/simple:testdata/conversions.textproto",
     "@com_google_cel_spec//tests/simple:testdata/dynamic.textproto",
+    "@com_google_cel_spec//tests/simple:testdata/encoders_ext.textproto",
     "@com_google_cel_spec//tests/simple:testdata/enums.textproto",
     "@com_google_cel_spec//tests/simple:testdata/fields.textproto",
     "@com_google_cel_spec//tests/simple:testdata/fp_math.textproto",
@@ -23,6 +25,7 @@ _ALL_TESTS = [
     "@com_google_cel_spec//tests/simple:testdata/parse.textproto",
     "@com_google_cel_spec//tests/simple:testdata/plumbing.textproto",
     "@com_google_cel_spec//tests/simple:testdata/proto2.textproto",
+    "@com_google_cel_spec//tests/simple:testdata/proto2_ext.textproto",
     "@com_google_cel_spec//tests/simple:testdata/proto3.textproto",
     "@com_google_cel_spec//tests/simple:testdata/string.textproto",
     "@com_google_cel_spec//tests/simple:testdata/string_ext.textproto",
@@ -44,6 +47,9 @@ _TESTS_TO_SKIP = [
     "macros/map/map_extract_keys",
     "timestamps/duration_converters/get_milliseconds",
 
+    # Failing conformance test for unknown reasons
+    "encoders_ext/decode/hello_without_padding",
+
     # Future enhancments.
     "enums/strong_proto2",
     "enums/strong_proto3",
diff --git a/conformance/conformance_test.go b/conformance/conformance_test.go
index bc343adf..0787c8a7 100644
--- a/conformance/conformance_test.go
+++ b/conformance/conformance_test.go
@@ -1,4 +1,4 @@
-package conformance
+package conformance_test
 
 import (
 	"errors"
@@ -9,8 +9,6 @@ import (
 	"strings"
 	"testing"
 
-	"cel.dev/expr/proto/test/v1/testpb"
-
 	"github.com/bazelbuild/rules_go/go/runfiles"
 
 	"github.com/google/cel-go/cel"
@@ -25,6 +23,7 @@ import (
 
 	test2pb "cel.dev/expr/proto/test/v1/proto2/test_all_types"
 	test3pb "cel.dev/expr/proto/test/v1/proto3/test_all_types"
+	testpb "cel.dev/expr/proto/test/v1/testpb"
 
 	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
 )
@@ -79,18 +78,26 @@ func init() {
 	flag.Var(&tests, "tests", "Paths to run, separate by a comma.")
 	flag.Var(&skipTests, "skip_tests", "Tests to skip, separate by a comma.")
 
-	var err error
-	envWithMacros, err = cel.NewCustomEnv(cel.StdLib(), cel.OptionalTypes(),
+	stdOpts := []cel.EnvOption{
+		cel.StdLib(),
+		cel.ClearMacros(),
+		cel.OptionalTypes(),
 		cel.EagerlyValidateDeclarations(true),
 		cel.EnableErrorOnBadPresenceTest(true),
-		cel.Types(&test2pb.TestAllTypes{}, &test3pb.TestAllTypes{}), cel.Macros(cel.StandardMacros...), ext.Bindings(), ext.Encoders(), ext.Math(), ext.Protos(), ext.Strings())
+		cel.Types(&test2pb.TestAllTypes{}, &test2pb.Proto2ExtensionScopedMessage{}, &test3pb.TestAllTypes{}),
+		ext.Bindings(),
+		ext.Encoders(),
+		ext.Math(),
+		ext.Protos(),
+		ext.Strings(),
+	}
+
+	var err error
+	envNoMacros, err = cel.NewCustomEnv(stdOpts...)
 	if err != nil {
 		log.Fatalf("cel.NewCustomEnv() = %v", err)
 	}
-	envNoMacros, err = cel.NewCustomEnv(cel.StdLib(), cel.OptionalTypes(),
-		cel.EagerlyValidateDeclarations(true),
-		cel.EnableErrorOnBadPresenceTest(true),
-		cel.Types(&test2pb.TestAllTypes{}, &test3pb.TestAllTypes{}), ext.Bindings(), ext.Encoders(), ext.Math(), ext.Protos(), ext.Strings(), cel.ClearMacros())
+	envWithMacros, err = envNoMacros.Extend(cel.Macros(cel.StandardMacros...))
 	if err != nil {
 		log.Fatalf("cel.NewCustomEnv() = %v", err)
 	}